Electret Condenser Mic - Read Values?

Forum 2005-2010 (read only) Hardware Interfacing
1

I'm pretty new to the Arduino. While I've had some success with the basic LED controls and the programming is well within my grasp, the electronics end is confusing me.

I have a specific project in mind which requires reading volume levels form an electret microphone unit. I've tried connecting the power to 5v power, the gnd to ground, and the output to analog 1. When I try reading values, I get something in the 450-490 range, but with little to no variation regardless of the ambient volume. I'm guessing the voltage is building up and I need to dump it, but I'm not sure how.

I've been looking for some tutorials on microphones, but while I can find plenty on piezo knock sensors and photocell sensors, I see nothing on actual microphone sensing. Can anyone direct me to a HOWTO or some resource where I can figure out how to interface an Arduino with an electret mic?

2

There was a project discussed a few months back that used microphones connected to the Arduino, the post that has links to info on the mic interface is here:
http://www.arduino.cc/cgi-bin/yabb2/YaBB.pl?num=1202056662/15#20

3

Thanks for your response, but unless I'm missing something, that thread appears to only discuss the software. I need to figure out the hardware.

4

clicking that link shows post #20 at the top of the page. this post mentions the op amps used and gives links to more info.

5

Sparkfun is working on something that seems like its exactly what you need, it's a simple 100X op-amp breakout:

http://www.sparkfun.com/commerce/news_archive.php (scroll down to the news for April 16th)

6

I thought I would just update this link. Since I stumbled across this, maybe someone else has to.
Here is the link to the break out mentioned in the previous post.

7

Also look at the schematic here:-
http://interface.khm.de/index.php/labor/experimente/arduino-realtime-audio-processing/

for the hardware input.